Thanks, jon, and more on that with the roundtable coming up today, the another top story the man in negotiating with nuclear deal, dr. Javad zarif is here. But first, terry moran on a dynamic week of diplomacy. Reporter: Absolutely, george, what we have seen this week represents the possibility of a stunning diplomatic breakthrough. But there's a lot of work to do. A week of head-spinning. In the making. Just now I spoke on the phone with rouhani. Reporter: So, with a 15-minute phone call, 34 years of bitter relations thawed ever so slightly. 1979 was the turning point, the shah of iran, a key american ally, toppled in a revolution. And a few months ago, the storming of the u.S. Embassy in iran. Enemies ever since. But the election of 64-year-old of rouhani in june brings hope. He's leashed a charm offensive on twitter and in interviews including with christiane amanpour on cnn. Translator: I bring peace and friendship. Reporter: So, when he arrived in new york for a meeting at the u.N. Anticipation was running high and secretary of state kerry met with his irani counterpart javad zarif. But this new chapter is fraught with risks for both sides. Can iran be trusted? President obama seems skeptical. The test will be meaningful, transparent and verifiable actions. Reporter: Another problem, rouhani is not the ultimate power in iran. The supreme leader ayatollah is. Translator: The supreme leader I can tell you, has given his permission for my government to negotiate freely on these issues. Reporter: The next step are likely to be small ones not big ones, confidence-building measures in advance of a meeting in october. Iran could agree to release western prisoners, including the american christian pastor and the u.S. Could ease some sanctions. George, the bottom line is, after these historic headlines this week, now comes the hard part, the really hard part. Let's get more on that hard part from iran's foreign minister, dr. Zarif joins us. Welcome back to "this week." Your first time in 26 years. Yes. It's been a long time. This week, analysts in the middle east have called the events a game-changer, one even liking it to the fall of berlin wall. Is that your view? Has there been a fundamental shift in the u.S. And iran? I think we have taken the first steps, an important step for both the u.S. And iran and for the international community. An issue that I believe shouldn't have become an issue in the first place, but in the first place, but it has unfortunately become a global problem and now we need to resolve it and the resolution of that issue will be a first step, a necessary first step, towards removing the tensions and doubts and misgivings that the two sides have had about each other for the last 30-some years. That is of course the nuclear issue, but there's a lot of skepticism, as you know, the ability of president rouhani and you to deliver on any deal. Analysts look at the fact that there wasn't a handshake, only a phone call, as a sign of weakness. And many western observers believe that your supreme leader won't do what it takes to back up a deal, can you assure that he will back up a deal that you negotiate? Iran and the united states are similar in many ways. One is, we both have pluralistic societies where difference of views exist and I think it's very healthy, of course -- but he has the final say? Of course, we have to do it with mutual respect and mutual interest. We believe that, if the united states is ready to recognize iran's rights, to respect iran's rights and move from that perspective, then we have a real chance and we negotiate with the full authority. We know what we want to achieve. We know that iran is not seeking a nuclear weapon. In fact, what I told the foreign ministers and the secretary of state, in the meeting, I told them that having an iran that does not have nuclear weapons is not just your goal, it's first and foremost our goal. As you know, there's a lot of skepticism about that. Buut secretary kerry in an interview that's going to air tonight, has laid out some concrete steps iran can take to prove they don't want a nuclear weapon. He here's what he had to say. They could immediately open up inspection of the facility, they could immediately sign the protocols, the additional protocols of the international community regarding inspections. They could offer to cease enrichment above a certain level. Is iran prepared to do that? Well, iran is prepared to start negotiating. I'm sure secretary kerry doesn't want to dictate to us what we should or shouldn't do. We're willing to do negotiates. The united states has to do certain things very rapidly. What do you need from the u.S.? To dismantle the sanctions. That's targeting ordinary iranians. Now, despite all of the claims to the contrary it's impossible to open a letter of credit from a bank to buy medicine for ian patients because there has been, in fact, blind sanctions against banks dealing with iran. There has been a lot of arm twisting by the united states. By certain elements within the u.S. Government which have tried to put pressure on ordinary iranian people. Iranians have showed during the last election they put their trust in the ballot box, they put their trust in the government. They want to form a position of strength. True flexibility. And that is what -- sanctions are not a useful tool of implementing policy. And the united states needs to change that. I understand that's your demand. In return, is iran prepared to stop enriching uranium at levels they're now enriching it? But that's on the table? Negotiations are on the table to discuss various aspects of iran's enrichment program. Our right to enrich is nonnegotiatable. But you need to enrich above 20%. We do not need military-grade uranium. That is a certainty and we will not move in that direction. But what is necessary is for the two sides to sit together and reach a common objective. We should not have two competing objectives. Let me explain to you, after the break up of the soviet union one of the concerns that you had and in the west and i shared those concerns was that all of these scientists that were involved in the nuclear program were now unemployed and they could go to the black market, seeking employment opportunities. Now, we have a large pool of iranian scientists. We have an indigenous iran nuclear program. Israel cannot kill all of our scientists. They have unfortunately assassinated some of them and no one has raised an eyebrow about it. Which is a source of great concern to us. The united states supposed to be against terrorism is allowing terrorists to kill innocent iranian scientists. All these scientists, the best way to ensure that the iranian nuclear program will remain peaceful is to make sure that these scientists operate in a facility or facilities observed by international observers. Including surprise inspections? Oh, yeah, we already have surprise inspections. We are moving in that direction. As you know, when I was negotiating our nuclear issue in THE EARLY 2000s, WE HAD -- WE Were implementing the additional protocol on a voluntary basis. Which provides for surprise inspections. Unfortunately at that time, the u.S. Administration, at that time, had different objectives. All facilities at that time, we're talking about 2003 to 2005 when we were negotiating, all facilities were open to the iaea. They were able to observe all of them. Only after you were caught. The iaea said that although iran had not declared its activities, now that we see those activities none of them had been diverted to military use. No question that iran ever had military motive. We're prepared to address those problems. We need to see -- lack of confidence is unfortunately mutual. As the president said, both president obama and president rouhani have said, there have been 34 years of building up of this mutual distrust, we need to move in that direction of removing some of that mistrust through mutual steps that each side needs to take. In order to convince the other side that its intentions are positive and for a better future for all of us. Netanyahu is on his way to the united states. On his way, at the airport, his departure, he called the moves by you and president rouhani this week a smile attack. British sunday times said that he'll be presenting intelligence to president obama that iran already has enough enriched uranium and testing weapons. Your response? A smile attack is much better than a lie attack. Mr. Netanyahu and his colleagues have been saying since 1991, and you can refer to your records, that iran is six months away from a nuclear weapon. We're 22 years after that and they are still saying we're six months away from nuclear weapon. I think this six-month time limit is something that's causing -- you're not six months from a nuclear weapon? We're not seeking nuclear weapons. We're not six years away from nuclear weapons. We don't want nuclear weapons. We believe that nuclear weapons are detrimental to our security. We believe that those who have illusion that nuclear weapons provide security are badly mistaken. We need to have a world free of nuclear weapons. I argued for 90 minutes that the use of nuclear weapons under any circumstances is illegal. Our leader has a religious verdict that the use of nuclear weapons is contrary to religious doctrine. So, these are our positions. Israel has 200 nuclear warheads. Israel is the source of aggression and violation of human rights of the palestinian people. It shouldn't continue to lie to the american people and to the world and mislead everybody. But you don't want nuclear weapons why enrich uranium to the levels you're enriching? Because that's our right. We came to the market requesting -- we own 10% of a european company that produces enriched uranium. We haven't been able to get a single gram of uranium that we need for the reactor. Not accidentally, in fact intentionally built by president eisenhower under the action for peace program. Not only the united states not providing the fuel for that reactor itself built in iran in THE 1950s IT'S PREVENTING OTHERS From providing us with fuel. What should we do? Should we lie down and die? No. We rely on our own capabilities and we produce them. Now, after -- they were hoping we can't. We couldn't produce them. After we were able to do it, now they say you shouldn't. We can't start history at the time of our choosing. The background has to be addressed, the historical aspects have to be addressed. Historical sources of iran very serious and deep mistrust of the behavior of the united states needs to be addressed and we should take concrete steps, concrete steps, one after another. We haven't forgotten the fact, when iraq used nuclear weapons against iran, that the united states blamed us for the use of chemical weapons, these are facts that are fresh in the minds of iranians. We're willing to show flexibility, not forget that. We may be willing forgive as president mandela said once. But we're not going to forget. You mentioned history. Both you and president rouhani have gone farther than your predecessors. In acknowledging and condemning the massacre of jews in world war ii. You said iran has never denied the holocaust. The man who was perceived to denying it is now gone. The website of the supreme leader, right now, on his website, in english, he refers to the myth of the massacre of the jews as the holocaust? Do you endorse or reject? I have spoken to the leader on this issue. He rejects and condemns the killing of innocent people. But is the holocaust a myth? No. The holocaust is not a myth. It said it right there. If it said it, it's a bad translation, and it's translated out of context. He was talking about the reaction to somebody talking about the historical incident and requiring research about that historical incident and said, what is it that people are so upset? That somebody is simply asking that we should do some studies. But, you see, this is a problem when you translate something from persia to english, you may lose some of the meaning. This has been unfortunately the case several times over. The point is, we condemn the killing of innocent people. Whether it happened in nazi germany or whether it's happening in palestine. holocaust was a heinous crime, it was a genocide, it must never be allowed to be repeated. But that crime cannot be and should not be a justification to trample the rights of iranian people for 60 years. We should abandon this game and start recognizing the fact that without respect for the rights of the palestinians we will never have peace in our region. Can the translation be changed? I'll talk to them. Let me ask you one final question. Your children were born in the united states. As I mentioned, you were on "this week" 26 years ago. When you hear those chants come up in iran, death to america, wt do you say to those iranians who say "death to america"? I think they're talking about policy. We're on record that we have no quarrel with the american people. American people are nice, peace-loving, generous people that come to the aid of people in need all over the world. And this is what we respect and have a lot of admiration for. It's the policies of the u.S. Government which has unfortunately been the source of instability in our region for many years. The united states supported dictators. It would be amazing for american people to know what types of governments in our region have been supported by the united states. But the iranians -- but the iranians feel it with their flesh the type of regime that govern them because of the support of the u.S., Some of the countries in our region continue to experience this. The fact that the united states supports whatever policy by israel is another indication that the united states needs to revisit some of its policies and move forward. Thank you for your time this morning, dr. Zarif. Welcome back to "this week." Thank you.

This transcript has been automatically generated and may not be 100% accurate.

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